Shipping or storage containers are used in conjunction with compatible container transport vehicles in a variety of different industries for hauling bulk materials including for example, scrap metal. The container transport vehicle typically includes a roll-on, roll-off mechanism for loading the containers onto the frame of the transport vehicle. The containers can then be hauled to their particular destination where the hauled material is dumped. Typically, the containers are designed to be dumped through a hinged rear door on the containers which has hinges either on the top or side of the container. One way in which the rear dumping of the containers can be accomplished is by providing the container transport vehicle with a tilt mechanism which tilts the shipping container allowing the hauled material to slide out of the rear of the container. If the hinges are positioned on the top of the rear doors, however, the hinged door limits the clearance which is available for the dumping operation. In addition, hinges located on either the top or the side of the container are susceptible to damage during hauling and dumping.
In order to ensure that the hinged rear door does not open during the hauling operation, the door is provided with a latch which must be released manually prior to dumping and then manually re-engaged once the hauled material is dumped. Thus, when the transport vehicle reaches the dump site, the operator of the transport vehicle must exit the cab, unlatch and open the rear door and then return to the transport vehicle's control panel, which is generally located in the cab of the transport vehicle, to execute the dumping operation. Once the dumping operation is completed, the operator must once again exit the cab to close and latch the rear doors. Obviously, this procedure is time-consuming, inconvenient, and creates a potentially unsafe condition with the possibility of injury to the vehicle operator, particularly during inclement weather.
One system which is used to automatically open the tailgate of containers that have tailgates which pivot upward relative to the container during a dumping operation utilizes a limited rotating cam which is attached to a vehicle tilt mechanism for tilting the container. This cam is also attached to a hydraulic cylinder for actuating the tilt mechanism. The hydraulic cylinder when actuated first rotates the cam which then contacts an arm on the tailgate and if the resistance of the tailgate required to rotate the tailgate is lower than the resistance required to tilt the container and the tilt mechanism, the tailgate rotates open and the container is then tilted to dump the container. Specifically, during the dumping operation, the hydraulic cylinder extends the piston rod in order to rotate the cam for the cam to push the tailgate such that it pivots into the open position. However, the rotation of the cam subjects the container to forces which act to push the container off the container transport vehicle. This arrangement can subject the container, container tailgate, container transport vehicle, and container loading and tilt mechanisms to some extreme forces which can have a detrimental effect on the stability and reliability of the dumping operation. Compensating for these forces may require specially designed containers, container tailgates, and container transport vehicle components which could significantly increase the cost of the container and the container transport vehicle.